Gregory W. Lester, PhD, is a clinical, consulting, and research psychologist with practices in Colorado and Texas. Dr. Lester has presented over 2,000 personality disorders trainings to over 200,000 professionals in every major city in the United States, Canada, and Australia. In his nearly 40 years of clinical practice, Dr. Lester has treated over 1,000 personality disorder cases and has performed psychological evaluations on over 2,500 individuals. He is the author of nine books, including Diagnosis, Treatment, and Management of Personality Disorders, which is the largest-selling front-line clinical manual on diagnosing, treating, and managing personality disorders. Dr. Lester’s research and articles have appeared in publications including The Journal of the American Medical Association, The Western Journal of Medicine, The Yearbook of Family Practice, The Journal of Behavioral Therapy, The Journal of Marriage and Family Therapy, The Handbook of Depression, Transactional Analysis Journal, Living Word Magazine, The Priest Magazine, and The Houston Lawyer.